Collection
- Patricia Hill Burnett papers, 1967-2002 (majority within 1967-1987)1
- Patrick Henry Kelley papers, 1910-19241
- Paul C. Hillegonds Papers, 1964-1996 (majority within 1978-1996)1
- Paul Gordon Goebel papers, 1942-19641
- Peter Barbeau papers, 1789-19091
- Peter White Papers, 1848-19151
- Ransom Dunn papers, 1796-19001
- Raymond J. Smit Papers, 1960-19771
- Regina Hay papers, 1930-19661
- Rice Aner Beal papers, 1843-18831
- Richard C. Van Dusen Papers, 1954-19721
- Robert H. Brucker papers, 1914-19671
- Roger Irving Wykes papers, 1889, 1907-19381
- Rollo G. Conlin Papers, 1948-19661
- Roscoe O. Bonisteel Papers, 1903-19721
- Rosemary Mason Ogden papers, 1946-19501
- Roy Dikeman Chapin Papers, 1886-1945 (majority within 1910-1936)1
- S. John Byington Papers, 1964-19721
- Samuel D. Pepper Papers, 1893-19521
- Shaw Family (Adrian, Mich.) papers, 1840-1938 (majority within 1860-1890)1